The invention pertains to a straight connection piece that is partially inserted, approximately half-way, into hollow profiles that are connected together end-to-end, said hollow profiles being used to form a spacer frame or spacer for insulated glass panes, wherein the cross section of the straight connector fits into the inner hollow section of the hollow profile and approximately corresponds to it at least in areas, with a centered recess on the back of the connector that faces the outer crosspiece of the hollow profile in the installed position, with the ends of the outer crosspiece of the hollow profiles that face each being deformable inwardly into the recess.
A straight connector of this type is known from EP 0 133 655 B2 and from EP 0 330 906 B1 and has been shown to be particularly useful with regard to the mutual alignment of the hollow profiles or hollow profile parts to be connected. The recess at the back of this prior art straight connector has a minimal depth and is bordered at its lateral ledges by a raised area. Furthermore, inside the recess is a projecting flat spacer so that the depth at this point of the recess is further reduced. This recess, then, only allows a minimal compression using the outer crosspiece of the hollow profiles to be connected. In order to nevertheless create a sealed abutment of the hollow profiles at the point of connection, the known straight connectors have projecting stops that hold the ends of the hollow profiles to be connected at a distance. This is intended to facilitate the penetration of sealant into the seams. This makes the formation of a sealed point of connection of the hollow profiles dependent on sufficient sealant being provided in this area and that it be fed through narrow gaps, which requires very careful procedures.
From DE 32 43 692 A1, a straight connector is known of this type that is formed from individual pieces. In the direction of longitudinal extension, this straight connector has an uninterrupted piece without a recess at its side that faces an inner crosspiece of the hollow profiles in its installed position, said uninterrupted piece forming a U-shaped cross section together with side pieces. Therefore, the narrow sides of the U-sides of this straight connector face the outer crosspiece of the hollow profiles. Inside the U-cross section are crosspieces that are at a distance to one another at the center of the straight connector so that each of the outer crosspieces of the hollow profile can be bent inward into the interior of the straight connector somewhat, provided that this is permitted by the side pieces of the hollow profile in this area. This allows the outer crosspiece of the hollow profile to be pressed only minimally inward in this case as well, whereby a narrow opening arises between the outside ends of the crosspieces of these hollow profiles through which to allow seal material. At the side facing the inner cross section, this straight connector also has a spacer to produce a peripheral seam at the point of abutment between the hollow profiles to be connected. Thus, it is difficult to produce a good and secure seal of the points of abutment of the hollow profiles to be connected. Therefore, the danger arises in pushing in the hollow profiles that the side pieces will bulge outward so that the dimensional stability, which is absolutely required in order to maintain a separation between two parallel panes of an insulating window, is not ensured. The common inward pushing of the outside of the hollow profile against the resistance of the outside pieces can even somewhat push the hollow profiles to be connected away from one another, under certain circumstances.